The primary objective of this SBIR effort is to develop a novel ultrathin (1~2 mm in diameter) scanning fiber endoscope (SFE) with simultaneous 2D/3D surface imaging capability. The proposed 3D-SFE will be able to provide, for the first time, dense 3D XYZ surface data that is co-registered with its 2D RGB counterpart, making 3D imaging an inherent part of SFE imaging capability without requiring users to perform any special manipulations or to take multiple images. The novel 3D imaging capability would greatly enhance the functionality of the existing SFE and enable it to perform, with its miniature probe size of 1~2 mm in diameter, a broad range of minimally invasive surgery procedures that were previously impossible to do. Unique features of the proposed novel 3D-SFE are: 7 High resolution full color 2D video image; 7 Unprecedented 3D imaging capability, with simultaneous and co-registered 2D and 3D image acquisition, possibly at video rate; 7 Single fiber scanner to generate stereo 3D images. 7 Dynamically adjustable field of view and image resolution; 7 Miniature size of the endoscope (~1 mm in diameter); 7 Extreme flexibility; and 7 Powerful 2D/3D image processing capability for minimally invasive surgeries. Xigen LLC proposes this comprehensive SBIR project, based on our strong collaborations and partnership with leading researchers/clinicians in multiple universities and hospitals. The Xigen team has long history and proven experience of attacking significant yet difficult 3D imaging problems in biomedical applications. Working closely with the research and clinical teams at the University of Washington who have developed multiple versions of working 2D scanning fiber endoscopes, we will develop full scale design, algorithms, hardware, software, and packaging for the 3D-SFE system, making it an integrated endoscopic image-guided system for minimally invasive surgeries that can access many sites that is currently impossible for existing endoscopes to do due to its ultra-thin diameter. This SBIR support will support thorough optical design, opto-electro-mechanical engineering development, 3D algorithmic development, and extensive tests. In Phase 1, the feasibility of the novel 3D-SFE will be thoroughly investigated. In Phase 2, working closely with clinical experts on our team, we will develop two fully functional 3D-SFE systems. We have streamlined our clinical study plan and focused on using 3D surface imaging capability for minimally invasive surgeries, such as otolaryngology surgeries (access sinus, middle ear, inner ear and skull based surgeries), and eye surgeries and drug placement on optic nerves. Proprietary Information of XIGEN LLC. 0 NIH SBIR PAR-09-220